arXiv subjects

Jing Shu

Publications and source records attributed to Jing Shu.

At least 19 recordsLinked to original sources

arXiv2026

Astrophysical Graviton Squeezing Can Be Hidden in the Far-Field

While localized astrophysical sources can generate macroscopic graviton squeezing, their observable quantum signatures at far-field detectors remain unresolved. In this work, we investigate the propagation dynamics of the squeezed states using spatial quantum optics methods to evaluate correlation functions accessible to a local observer. Crucially, we reveal a severe kinematic conflict in same-cone measurements, which highly suppresses local quantum coherence. Consequently, these macroscopically squeezed states appear classically thermal to a single detector. Our results demonstrate that global squeezing does not guarantee local observability, and the measurable quantum signatures may be significantly weaker than what would be expected from the overall squeezing parameter of the state.

gr-qc↗

arXiv2026

Hardware-efficient quantum simulation of intense-field QED

Strong electromagnetic backgrounds make quantum electrodynamics a real-time nonperturbative problem involving dressed fermions and dynamical photons. We propose a trapped-ion protocol for simulating intense-field QED in $3+1$ dimensions in the Furry picture. The construction encodes photon modes in collective phonons and Volkov-dressed fermion modes in ion spins, combining native spin-phonon couplings with Clifford circuits that compress nonlocal Jordan--Wigner strings. For nonlinear Breit--Wheeler pair production, the protocol has polynomial resource scaling and is benchmarked against exact single-mode dynamics with controlled Trotter errors. With experimentally motivated phonon heating and dephasing, zero-noise extrapolation substantially reduces deviations in photon-survival and pair-production signals. These results provide a hardware-efficient route to intense-field particle-production dynamics beyond perturbative or static-field descriptions.

quant-ph↗

arXiv2026

Ferromagnetic broadband sensing of axionlike dark matter

Levitated particles have demonstrated ultrahigh sensitivity to magnetic fields and accelerations owing to their extremely low dissipation. Such systems have strong potential for fundamental physics research, particularly for the detection of axions and axionlike particles, well-motivated dark matter candidates spanning a broad mass range. In this context, both high sensitivity and large bandwidth are essential. Here, we demonstrate a levitated magnet magnetometer based on an engineered double-resonance mode, achieving an effective linewidth at its optimal sensitivity that is approximately three orders of magnitude broader than those of previous approaches. Together with a hard-magnet array that enhances the axion-induced signal and soft-ferromagnetic shielding that suppresses environmental magnetic noise, this system constitutes a hybrid ferromagnetic platform for axionlike dark matter searches. We search for axionlike dark matter through its photon coupling $g_{a\gamma}$ over the $40$-$3000\,\mathrm{Hz}$ frequency range and establish new direct limits in this frequency band. The best sensitivity is achieved near the upper resonance around $276\,\mathrm{Hz}$, where the magnetometer reaches a magnetic-field resolution of $0.7\,\mathrm{fT}$, corresponding to a limit of $g_{a\gamma}\sim10^{-7}\,\mathrm{GeV}^{-1}$. At this frequency, this result improves upon previous direct limits by more than four orders of magnitude. The demonstrated high-bandwidth levitated sensor may also enable a broad range of applications, including biological sensing and precision measurements.

hep-ex↗

arXiv2026

New Gauge Forces, Neutron Stars and Schwinger Neutrino Production

We investigate neutrino effects of new long-range forces arising from gauging $B-L$, $L_e-L_{\mu/\tau}$ or $L_{\mu}-L_{\tau}$ symmetries of the Standard Model. The leptonic potential generated by astronomical bodies, such as the Earth, the Sun or a neutron star, results in the Schwinger pair production of neutrinos charged under the new gauge symmetry. The oppositely charged particles accumulate in the potential well forming a degenerate Fermi gas, while equally charged particles fly away forming a steady flux of neutrinos. We find that, for the $B-L$ and $L_e-L_{\mu/\tau}$ forces, these effects are too weak to be observable. For the $L_{\mu}-L_{\tau}$ force these effects are significant in neutron stars if the gauge coupling is $g\gtrsim 10^{-18}$. The muonic force changes the element abundances of a neutron star in equilibrium and suppresses its $L_{\mu}-L_{\tau}$ charge. This invalidates the constraint on $g$ from neutron star mergers, at $g\gtrsim 10^{-17}$. Furthermore, for such values of $g$, the neutrino flux produced by the Schwinger effect could potentially be detected from a single young neutron star at a distance of $\simeq 100$ pc, with the typical neutrino energy $E_\nu\sim 100$ MeV. A dedicated search for such a signal will reassert the bound $g\lesssim 10^{-18}$.

hep-ph↗

arXiv2026

Entanglement Maximization and Symmetry Selection in Composite Higgs Models

Recent developments suggest that the extremization of quantum entanglement may provide a useful organizing principle for strong dynamics. While entanglement suppression characterizes low-energy QCD, we investigate the role of entanglement maximization in the electroweak symmetry breaking sector. Focusing on the Composite Higgs Model, we analyze the process $hh \to t\bar{t}$ by treating the fermionic helicity space as a bipartite quantum system. Maximal entanglement imposes nontrivial constraints on the fermionic effective theory and leads to two simple symmetry structures in the top sector. One is the Maximal Symmetry branch, characterized by the vanishing of the Higgs-dependent form factor $\Pi_1$ and the finiteness of the Higgs potential. The other is a generalized $Z_2$-matching branch relating the left- and right-handed top sectors. Our results establish a quantitative connection between entanglement structure and the naturalness of electroweak symmetry breaking, and suggest that the symmetry patterns of the strong sector may be understood from the perspective of entanglement extremization.

hep-ph↗

arXiv2026

Dark Matter Detection through Rydberg Atom Transducer

Ultralight bosonic dark matter with masses in the meV range, corresponding to terahertz (THz) Compton frequencies, remains largely unexplored due to the difficulty of achieving both efficient signal conversion and single-photon-sensitive detection at THz frequencies. We propose a hybrid detection architecture that integrates a dielectric haloscope, Rydberg-atom transducer, and superconducting nanowire single-photon detection within a unified cryogenic platform operating at $\lesssim 1\,\text{K}$. The dielectric haloscope converts dark matter into THz photons via phase-matched resonant enhancement, achieving form factors $C \sim 0.4$ and loaded quality factors $Q_L \sim 10^4$. A cold $^{87}$Rb ensemble then coherently up-converts the THz signal to the optical domain through six-wave mixing among Rydberg states. The intrinsic directionality and narrow bandwidth ($\Delta\nu_{\mathrm{atomic}} \sim 1\,\text{MHz}$) of this process provide extra suppression of isotropic thermal backgrounds. With 10 days of integration at $0.3\,\text{K}$, we project sensitivity to the axion-photon coupling $g_{a\gamma\gamma} \sim 10^{-13}\,\mathrm{GeV}^{-1}$ at $m_a \sim 0.4\,\text{meV}$, reaching the QCD axion band and opening the THz window for searches of both axion and dark photon dark matter.

hep-ph↗

arXiv2026

Cavity Multimodes as an Array for High-Frequency Gravitational Waves

Microwave cavities operated in the presence of a background magnetic field provide a promising avenue for detecting high-frequency gravitational waves (HFGWs). We demonstrate for the first time that the distinct antenna patterns of multiple electromagnetic modes within a single cavity enable localization and reconstruction of key properties of an incoming HFGW signal, including its polarization ratio and frequency drift rate. Using a 9-cell cavity commonly employed in particle accelerators as a representative example, we analyze the time-domain response of 18 nearly degenerate modes, which can be sequentially excited by a frequency-drifting signal. The sensitivity is further enhanced by the number of available modes, in close analogy to the scaling achieved by a network of independent detectors, enabling sensitivity to astrophysically plausible binary sources.

hep-ph↗

arXiv2025

Novel Light Dark Matter Detection with Quantum Parity Detector Using Qubit Arrays

We present the design and the sensitivity reach of the Qubit-based Light Dark Matter detection experiment. We propose the novel two-chip design to reduce signal dissipation, with quantum parity measurement to enhance single-phonon detection sensitivity. We demonstrate the performance of the detector with full phonon and quasiparticle simulations. The experiment is projected to detect $\gtrsim 30$ meV energy deposition with nearly $100\%$ efficiency and high energy resolution. The sensitivity to $m_\chi\gtrsim 0.01$ MeV dark matter scattering cross section is expected to be advanced by orders of magnitude for both light and heavy mediators, and similar improvements will be achieved for axion and dark photon absorption in the $0.04$-$0.2$ eV mass range.

hep-ph↗

arXiv2025

Symmetric Dicke States as Optimal Probes for Wave-Like Dark Matter

We identify symmetric Dicke states as the optimal quantum probes for distributed sensing of wave-like dark-matter fields. Within an ensemble-averaged quantum-metrological framework that incorporates the field's random phases and finite coherence, they maximize the Fisher information for short-baseline arrays with $N_d$ sensors and realize a robust $N_d^2$ enhancement. They also retain this collective advantage under amplitude-damping noise, whereas GHZ-type probes are highly fragile and rapidly lose their sensitivity once such noise is included. For two sensors at separations comparable to the dark-matter coherence length, the optimal entangled state acquires an additional spatial-correlation phase and outperforms both Dicke and independent probes. Our framework applies broadly to stochastic bosonic fields, including gravitational waves, and can be implemented with superconducting qubits, atomic ensembles, and NV centers.

hep-ph↗

arXiv2025

Collapse of Axion Domain Wall Induced by Helical Primordial Magnetic Fields

Stable domain wall (DW) must decay to avoid overclose the Universe. A commonly used solution is to slightly break the PQ symmetry by introducing a bias term in the potential. In this work, we propose an alternative, symmetry-preserving mechanism: coupling the axion field to a helical primordial magnetic field (PMF) via the Chern-Simons term. Using three-dimensional lattice simulations, we evolve the DW network and demonstrate that it can successfully drive DW decay. Our quantitative results further show that the correlation length of the PMF plays a crucial role in determining the decay rate of the DW network and the resulting axion and gravitational wave radiation.

astro-ph.CO↗

arXiv2025

Search for Ultralight Dark Matter with Quantum Magnetometry in the Earth's Cavity

Ultralight dark matter candidates, such as axions and dark photons, are leading dark matter candidates. They may couple feebly to photons, sourcing oscillating electromagnetic signals in the Earth's conducting cavity formed between the ground and the ionosphere, providing detectable magnetic field signatures at wavelengths above the Earth's size. We carry out a project aiming to search for new physics using an unshielded high-sensitivity atomic magnetometer, termed the Geomagnetic Probe for nEw physiCS (GPEX). In this work, we report our first search for axion and dark photon dark matter, conducted in the desert of XiaoDushan in Gansu Province, China. Analysis of the collection of one-hour data shows no robust evidence for axion- or dark photon-induced magnetic signals. Correspondingly, we set the constraints on the axion-photon coupling with $g_{a\gamma\gamma} < 7\times10^{-10}\, \mathrm{GeV^{-1}}$ and the dark photon kinetic-mixing parameter $\epsilon < 2\times10^{-6}$ in the mass range $3.5 \times 10^{-16}\, \mathrm{eV} \sim 1.8 \times 10^{-14}\, \mathrm{eV}$. Our findings demonstrate the feasibility of using ground-based quantum magnetic sensors for ultralight dark matter searches. Future networks of such detectors operating over extended periods could improve the sensitivity by about three orders of magnitude.

hep-ph↗

arXiv2025

Probing Axion via M\"ossbauer Spectroscopy

We propose using the ultra-narrow 88 keV M\"ossbauer transition in $^{109}$Ag to search for QCD axion dark matter. The sub-eV axion field oscillates coherently, inducing a time-varying effective $\bar{\theta}_{\rm QCD}$ angle. This, in turn, modulates the nuclear binding energy. From existing linewidth measurements, we derive constraints on the $f_a^{-1}$-$m_a$ plane that already surpass other laboratory bounds. We further detail an experimental setup to directly probe this time-dependent signature via precision M\"ossbauer spectroscopy in the gravitational potential. This Letter demonstrates that this approach can significantly extend search capability and probe a vast, unexplored region of axion parameter space. Particularly, this setup can probe axion masses beyond the reach of existing experiments, such as atomic-clock measurements, offering a powerful new way for exploring higher-mass axion dark matter. The sensitivity has the potential to be further improved with advancing experimental capabilities.

hep-ph↗

arXiv2025

Everything-Grasping (EG) Gripper: A Universal Gripper with Synergistic Suction-Grasping Capabilities for Cross-Scale and Cross-State Manipulation

Grasping objects across vastly different sizes and physical states-including both solids and liquids-with a single robotic gripper remains a fundamental challenge in soft robotics. We present the Everything-Grasping (EG) Gripper, a soft end-effector that synergistically integrates distributed surface suction with internal granular jamming, enabling cross-scale and cross-state manipulation without requiring airtight sealing at the contact interface with target objects. The EG Gripper can handle objects with surface areas ranging from sub-millimeter scale 0.2 mm2 (glass bead) to over 62,000 mm2 (A4 sized paper and woven bag), enabling manipulation of objects nearly 3,500X smaller and 88X larger than its own contact area (approximated at 707 mm2 for a 30 mm-diameter base). We further introduce a tactile sensing framework that combines liquid detection and pressure-based suction feedback, enabling real-time differentiation between solid and liquid targets. Guided by the actile-Inferred Grasping Mode Selection (TIGMS) algorithm, the gripper autonomously selects grasping modes based on distributed pressure and voltage signals. Experiments across diverse tasks-including underwater grasping, fragile object handling, and liquid capture-demonstrate robust and repeatable performance. To our knowledge, this is the first soft gripper to reliably grasp both solid and liquid objects across scales using a unified compliant architecture.

cs.RO↗

arXiv2025

Quantum-Enhanced Dark Matter Search Using Cat States

Quantum metrology has recently emerged as a powerful approach for dark matter (DM) searches, particularly using nonclassical bosonic states in microwave cavities that are sensitive to weak signals. Nonclassical cat states - macroscopic superpositions of coherent states featuring sub-Planck interference structures - offer promising advantages for high-precision measurements. However, their practical utility in DM search remains unexplored. Here, we report the first experimental application of four-component cat states within a high-quality superconducting microwave cavity to search for dark photons, a potential DM candidate. We demonstrate an 8.1-fold enhancement in the signal photon rate and constrain the dark photon kinetic mixing angle to an unprecedented $\epsilon < 7.32 \times 10^{-16}$ near 6.44~GHz (26.6~$\mu$eV). By employing a parametric sideband drive to actively tune the cavity frequency, we achieve dark photon searches and background subtraction across multiple frequency bins, yielding a sensitivity at the $10^{-16}$ level within a 100~kHz bandwidth. Our cat-assisted DM (CaD) search and frequency-scanning techniques demonstrate substantial improvements over previous results, promising potential implications in quantum-enhanced searches for new physics.

quant-ph↗

arXiv2025

An Efficient On-shell Framework for EFT Matching

Standard techniques for one-loop EFT matching often have gauge and basis redundancies, while strictly 4-dimensional on-shell methods fail to capture rational terms. To resolve this, we develop an efficient, channel-based on-shell framework for one-loop matching. Our method reconstructs the local hard-region amplitude by sewing tree amplitudes across double cuts, employing a mass-shift prescription to recover d-dimensional internal states. This d-dimensional sewing retains rational terms and integrates them seamlessly with ordinary cut-constructible contributions. The local amplitude is expanded in the hard region and directly projected onto non-redundant, on-shell EFT amplitude bases. With tadpoles and kinematically independent bubbles systematically fixed by an explicit subtraction convention, our framework successfully merges the rigorous extraction of rational Wilson coefficients with the gauge-invariant elegance of modern amplitude methods.

hep-ph↗

arXiv2025

Testing Nambu-Goto approximation of cosmic string by lattice field simulations

The precise calculation of gravitational wave (GW) from cosmic string networks is of significant theoretical and experimental interest. The Nambu--Goto (NG) approximation has long been employed to calculate GW emission from such networks; however, its validity has never been systematically verified. We perform large-scale zero-temperature Abelian-Higgs lattice simulations under different gauge couplings, and compare them with NG predictions. We find excellent agreement in the power-law region for near-global strings but strong deviation for strongly coupled local strings with $m_v/m_s \sim 1$, quantitatively establishing the breakdown of the NG approximation. Additionally, we confirm that particle emission significantly dominates the energy loss of the string network, with the ratio of GW energy to particle energy approximately $10^{-3}$ to $10^{-2}$ for both near-global and local string scenarios.

astro-ph.CO↗

arXiv2025

Geomagnetic constraints on Millicharged Dark Matter

Millicharged particles are well-motivated dark matter candidates arising in many extensions of the Standard Model. We show that, despite their tiny coupling $e_m$ to photons, millicharged dark matter (mDM) in the Earth's geomagnetic field can generate a quasi-static, monochromatic magnetic signal with angular frequency twice the mDM mass. Using null results from the SuperMAG and SNIPE Hunt collaborations, we constrain the effective charge of bosonic mDM in the mass range $10^{-18}$--$10^{-14}\,\text{eV}$. The resulting upper bounds exceed stellar cooling constraints by over thirteen orders of magnitude, demonstrating the power of this method.

hep-ph↗

arXiv2024

Pulsar Polarization Array Limits on Ultralight Axion-like Dark Matter

We conduct the first-ever Pulsar Polarization Array (PPA) analysis to detect the ultralight Axion-Like Dark Matter (ALDM) using the polarization data of 22 millisecond pulsars from the third data release of Parkes Pulsar Timing Array. As one of the major dark matter candidates, the ultralight ALDM exhibits a pronounced wave nature on astronomical scales and offers a promising solution to small-scale structure issues within local galaxies. While the linearly polarized pulsar light travels through the ALDM galactic halo, its position angle (PA) can be subject to an oscillation induced by the ALDM Chern-Simons coupling with electromagnetic field. The PPA is thus especially suited for detecting the ultralight ALDM by correlating polarization data across the arrayed pulsars. To accomplish this task, we develop an advanced Bayesian analysis framework that allows us to construct pulsar PA residual time series, model noise contributions properly and search for pulsar cross-correlations. We find that for an ALDM density of $\rho_0=0.4\,\textrm{GeV}/\textrm{cm}^3$, the Parkes PPA offers the best global limits on the ALDM Chern-Simons coupling, namely $\lesssim 10^{-13.5}-10^{-12.2}~{\rm GeV}^{-1}$, for the mass range of $10^{-22} - 10^{-21}~{\rm eV}$. The crucial role of pulsar cross-correlation in recognizing the nature of the derived limits is also highlighted.

astro-ph.HE↗